Re: [EVDL] Dissimilar metals on Headyways?
I had a look at the headway factory interconnects, they are plated steel I think as they are magnetic, could be nickel but they were strongly attracted to a magnet so I think steel. 1mm thick, 20mm wide. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
Nickel is ferromagnetic also. (Hence, Alnico magnets, the Ni being nickel.) http://en.wikipedia.org/wiki/Permeability_(electromagnetism) Nickel is right there with carbon steel in magnetic permeability, but it is much less susceptible to corrosion. Stamped steel with a nickel plate might be a good choice, provided the plating is done well. On Thu, Sep 25, 2014 at 4:49 PM, George Tyler via EV ev@lists.evdl.org wrote: I had a look at the headway factory interconnects, they are plated steel I think as they are magnetic, could be nickel but they were strongly attracted to a magnet so I think steel. 1mm thick, 20mm wide. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140925/b1552f80/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
The mangnetic properties will still be coming from the steel, even though Nickel is magnetic, because typically plating is done as thin as possible, so the Nickel won't contribute much to the magnetic properties. for example, if you would have nickel plated copper or alu, it won't have much magnetic properties. Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of David Nelson via EV Sent: Thursday, September 25, 2014 2:38 PM To: Michael Ross; Electric Vehicle Discussion List Subject: Re: [EVDL] Dissimilar metals on Headyways? I asked Jim of Headway-Headquarters what the end plates were and he said that they are nickel plated steel. On Thu, Sep 25, 2014 at 2:20 PM, Michael Ross via EV ev@lists.evdl.org wrote: Nickel is ferromagnetic also. (Hence, Alnico magnets, the Ni being nickel.) http://en.wikipedia.org/wiki/Permeability_(electromagnetism) Nickel is right there with carbon steel in magnetic permeability, but it is much less susceptible to corrosion. Stamped steel with a nickel plate might be a good choice, provided the plating is done well. On Thu, Sep 25, 2014 at 4:49 PM, George Tyler via EV ev@lists.evdl.org wrote: I had a look at the headway factory interconnects, they are plated steel I think as they are magnetic, could be nickel but they were strongly attracted to a magnet so I think steel. 1mm thick, 20mm wide. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
Yep, flux density is a bulk and dimensional property. Less material always means less contribution to the field that can be supported. I was talking about nickel as a substrate being notably ferromagnetic, not as a plating. On Thu, Sep 25, 2014 at 7:09 PM, Cor van de Water via EV ev@lists.evdl.org wrote: The mangnetic properties will still be coming from the steel, even though Nickel is magnetic, because typically plating is done as thin as possible, so the Nickel won't contribute much to the magnetic properties. for example, if you would have nickel plated copper or alu, it won't have much magnetic properties. Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of David Nelson via EV Sent: Thursday, September 25, 2014 2:38 PM To: Michael Ross; Electric Vehicle Discussion List Subject: Re: [EVDL] Dissimilar metals on Headyways? I asked Jim of Headway-Headquarters what the end plates were and he said that they are nickel plated steel. On Thu, Sep 25, 2014 at 2:20 PM, Michael Ross via EV ev@lists.evdl.org wrote: Nickel is ferromagnetic also. (Hence, Alnico magnets, the Ni being nickel.) http://en.wikipedia.org/wiki/Permeability_(electromagnetism) Nickel is right there with carbon steel in magnetic permeability, but it is much less susceptible to corrosion. Stamped steel with a nickel plate might be a good choice, provided the plating is done well. On Thu, Sep 25, 2014 at 4:49 PM, George Tyler via EV ev@lists.evdl.org wrote: I had a look at the headway factory interconnects, they are plated steel I think as they are magnetic, could be nickel but they were strongly attracted to a magnet so I think steel. 1mm thick, 20mm wide. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140925/738fa967/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
If I honeycomb arrange my cells I can get more to fit. The stock plates I have seen won't work as they are for square arrangements of cells, like this: http://www.manzanitamicro.com/components/com_virtuemart/shop_image/product/4_Cell_Bus_Bar_f_4e77a3a355a78.jpg Also, it isn't much effort and but is much knowledge gained to test Al vs. Cu. Since the cell is Al inside, it seems like Al might be better for that reason, but possibly worse for other reasons. Al wire is about 1/6 the price of Cu wire, but it would be a lot of work to hammer or crimp Al wire into a good shape for Headways. I called about electrically conductive Aluminum sheet -- it is not commonly used or stocked, and is very expensive (unlike the wire). So Al is either a lot of work or high cost, two more negatives I just learned about. Lee brings up a good point about the plates stressing the cell terminals. Here are some more data points on that front: o The cases on Headways are steel, so the cells are very strong. o The Headway plastic holders are surprisingly strong and rigid. http://www.manzanitamicro.com/components/com_virtuemart/shop_image/product/3_Cell_Plastic_H_4e77a2af4fd3f.jpg You have to push the cells in with a fair amount of force, the stress goes to the metal case. I made a 6x8 array with the plastic holders. That many cells weighs about 30 lbs (14 kg). To my surprise, I could lift opposite corners but couldn't detect the little 6x8 pack flexed or that the cells shifted at all. So maybe you can get away with plates on Headways better than for the large block prismatics. o To get the equivalent of cable cross section I need Cu plate about 0.022 in thick (the current with go through about 10 inches wide). That can bend a bit if flexed, but will still be pretty rigid between the posts... Hmmm, do I trust the Headway rings to be tough enough for plates or do something fancier with intercell connectors? Thanks all for the good ideas and discussion. Sent: Tuesday, September 23, 2014 at 11:50 AM From: Lee Hart via EV ev@lists.evdl.org To: g...@tylernz.com, Electric Vehicle Discussion List ev@lists.evdl.org Subject: Re: [EVDL] Dissimilar metals on Headyways? George Tyler via EV wrote: Why not just buy the link plates that headway sell, made for the purpose. Get the cell mounts at the same time? Are these just a flat bar that bolts directly between cells. If so, that's not a good way to do it. The cells will move slightly due to road bumps and vibration, The cell cases are plastic, which will expand and contract from temperature changes. The cases will also swell over time as the cells age. With rigid inter-cell jumpers, all this movement causes leaks and bad connections to develop over time. Your inter-cell cell jumpers should therefore have a bend or kink or other method to provide a little bit of flexibility or give to avoid straining the connections. This is true for *all* types of batteries; not just lithium. -- If you would not be forgotten When your body's dead and rotten Then write of great deeds worth the reading Or do these great deeds, worth repeating. -- Ben Franklin, from Poor Richard's Almanac -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub[http://www.evdl.org/help/index.html#usub] http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA[http://groups.yahoo.com/group/NEDRA]) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
Why not just buy the link plates that headway sell, made for the purpose. Get the cell mounts at the same time? -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Michael Ross via EV Sent: Tuesday, 23 September 2014 11:41 a.m. To: EVDL Administrator; Electric Vehicle Discussion List Subject: Re: [EVDL] Dissimilar metals on Headyways? If there is a platting house nearby, they won't charge much for a basket of copper bits. Could be far less trouble than manual tinning. Nickel might be better choice in that case. Of a flash of nickel under the tin. I would do tin/lead dip if I was not concerned about ROHS and had a plater still working with that. It is a much better coating in so many ways. If you could find an old solder pot (for tinning leads and such) you could do that yourself for smaller parts. On Mon, Sep 22, 2014 at 3:06 PM, EVDL Administrator via EV ev@lists.evdl.org wrote: On 22 Sep 2014 at 7:55, Roland via EV wrote: You can get the plated copper bus bars in long lengths and cut them to size. You will note that the cut ends will show copper. In wet locations, coat these cut ends with silver paint or epoxy silver paint. Why not tin them with solder? I would think that that would bond and protect better. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140922/6886f70e /attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
George Tyler via EV wrote: Why not just buy the link plates that headway sell, made for the purpose. Get the cell mounts at the same time? Are these just a flat bar that bolts directly between cells. If so, that's not a good way to do it. The cells will move slightly due to road bumps and vibration, The cell cases are plastic, which will expand and contract from temperature changes. The cases will also swell over time as the cells age. With rigid inter-cell jumpers, all this movement causes leaks and bad connections to develop over time. Your inter-cell cell jumpers should therefore have a bend or kink or other method to provide a little bit of flexibility or give to avoid straining the connections. This is true for *all* types of batteries; not just lithium. -- If you would not be forgotten When your body's dead and rotten Then write of great deeds worth the reading Or do these great deeds, worth repeating. -- Ben Franklin, from Poor Richard's Almanac -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
There is an infinitely easier way to do this - https://www.nde-ed.org/GeneralResources/MaterialProperties/ET/Conductivity_Al.pdf %IACS means the conductivity relative the International Annealed Copper Standard https://www.nde-ed.org/GeneralResources/IACS/IACS.htm It is a nice easy way to compare materials conductivity. On Mon, Sep 22, 2014 at 12:22 AM, via EV ev@lists.evdl.org wrote: I might well be fighting a losing battle, but for the price of 4 holes in a strip of material it has been a great education. Tonight I tested the different alloys of Al idea. Last time, 0.02 x 1.75 in strip of roof flashing aluminum: ~120 F temperature rise in ~15 seconds, cross sectional area 0.036 in^2 Tonight: 0.1 in diameter aluminum welding filler rod ~30 F temperature rise in ~90 seconds, cross sectional area 0.016 in^2 I was rather impressed that 1/2 the area had ~1/4 the temperature rise! My guess is the welding rod is a more conductive Al alloy than the roof flashing is the big difference. Sent: Sunday, September 21, 2014 at 11:03 AM From: Chris Tromley ctrom...@gmail.com To: evdragra...@email.com, Electric Vehicle Discussion List ev@lists.evdl.org Subject: Re: [EVDL] Dissimilar metals on Headyways? I think you're fighting a losing battle. Different alloys have an influence, but not enough to overcome the fact that copper has roughly twice the conductivity (both electrical and thermal) of aluminum. You'll need twice the cross-sectional area in aluminum as you would need with copper to achieve similar performance. Your 1.75 inch test shows a lack of proportionality, but that's likely due to short straps and how the current flows locally from the bolted joint. I'm thinking your best bet is to use copper conductors and be very sure all connections are thoroughly greased (Noalox, Vaseline, whatever) to ensure all moisture is excluded from the joint. And I would re-grease them once a year. Chris On Sun, Sep 21, 2014 at 2:54 AM, via EV ev@lists.evdl.org wrote:I thought folks would like to hear the results of some of my testing. 1/2 inch smashed copper pipe, 200 Amps for a 2S2P pack of 8 Ahr P (for Power) Headway cells: Things stayed cool. 1/2 inch by 0.02 inch braided strap with smashed copper pipe at connections: 5 F rise in 90 seconds at 200 A 1/2 inch by 0.01 inch Al: 200A, 80F to 200F in about 15 seconds! This was done in the oxidized state. 1/2 inch by 0.01 inch Al: 200A, 80F to 200F in about 15 seconds! This was done with sanding and immediate Noalox. 1.75 inch by 0.02 inch Al: 200A, 80F to 160F in about 30 seconds. The Al performed way worse than theory predicted, then I think I figured it out. Al roof flashing from Home Depot is apparently not a very conductive alloy of Al. I'd guess better Al would perform much closer to Cu. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub[http://www.evdl.org/help/index.html#usub] http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA[http://groups.yahoo.com/group/NEDRA]) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140922/d72c3737/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
Why not use tin plated copper bus bars. This is what we use in our electrical equipment. You can also get plated aluminum bus bars and wire terminals that is normally use in overhead line equipment. When purchasing bus bars, wire terminals, circuit breakers, circuit breaker panels and switch gear, some times in the larger fittings it, it may have a stamp on it CO-AL meaning that it is approve for for either Copper or Aluminum connections. You can get the plated copper bus bars in long lengths and cut them to size. You will note that the cut ends will show copper. In wet locations, coat these cut ends with silver paint or epoxy silver paint. Go to a local wholesale electrical supply house to see what sources and manufacturers they sell. Some times you may able to buy from them if you list yourself as a Electric Vehicle Research Systems or sometime like that. If you cannot purchase directly from them, find out what electrical contractors deals with this supplier and go to the electrical contractor to pick up a purchase order with all the items and stock numbers listed. Some times these electrical contractors may have varies lengths of these bus bars left over from a job. I plan to use plated copper bus bars when I use Li-Ion cells. Roland - Original Message - From: Lee Hart via EVmailto:ev@lists.evdl.org To: evdragra...@email.commailto:evdragra...@email.com ; Electric Vehicle Discussion Listmailto:ev@lists.evdl.org Sent: Sunday, September 21, 2014 11:22 PM Subject: Re: [EVDL] Dissimilar metals on Headyways? via EV wrote: I might well be fighting a losing battle, but for the price of 4 holes in a strip of material it has been a great education. Tonight I tested the different alloys of Al idea. Last time, 0.02 x 1.75 in strip of roof flashing aluminum: ~120 F temperature rise in ~15 seconds, cross sectional area 0.036 in^2 Tonight: 0.1 in diameter aluminum welding filler rod ~30 F temperature rise in ~90 seconds, cross sectional area 0.016 in^2 I was rather impressed that 1/2 the area had ~1/4 the temperature rise! My guess is the welding rod is a more conductive Al alloy than the roof flashing is the big difference. Great to see some actual test results! A quick comment: Pure metals are much more conductive than alloys. Most hardware store structural aluminum is going to be some alloy -- not what you want as an electrical conductor! Look up the conductivity of the various aluminum alloys and you'll see what I mean. Get some PURE aluminum to test. If you have to get it at Home Depot, then buy some aluminum *wire* and spread out the strands to make a flat strip. There are also aluminum solders. They actually work pretty well. You could place a bunch of strands of aluminum wire next to each other to make a flat bar, wrap a thin piece of aluminum flashing around them to hold them in position, and then solder them together at the ends. Drill a hole in the ends of the bar, and you have a high conductivity (yet somewhat flexible) inter-cell jumper. -- If you would not be forgotten When your body's dead and rotten Then write of great deeds worth the reading Or do these great deeds, worth repeating. -- Ben Franklin, from Poor Richard's Almanac -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htmhttp://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usubhttp://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.orghttp://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRAhttp://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140922/b4da8626/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
On 22 Sep 2014 at 7:55, Roland via EV wrote: You can get the plated copper bus bars in long lengths and cut them to size. You will note that the cut ends will show copper. In wet locations, coat these cut ends with silver paint or epoxy silver paint. Why not tin them with solder? I would think that that would bond and protect better. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
If there is a platting house nearby, they won't charge much for a basket of copper bits. Could be far less trouble than manual tinning. Nickel might be better choice in that case. Of a flash of nickel under the tin. I would do tin/lead dip if I was not concerned about ROHS and had a plater still working with that. It is a much better coating in so many ways. If you could find an old solder pot (for tinning leads and such) you could do that yourself for smaller parts. On Mon, Sep 22, 2014 at 3:06 PM, EVDL Administrator via EV ev@lists.evdl.org wrote: On 22 Sep 2014 at 7:55, Roland via EV wrote: You can get the plated copper bus bars in long lengths and cut them to size. You will note that the cut ends will show copper. In wet locations, coat these cut ends with silver paint or epoxy silver paint. Why not tin them with solder? I would think that that would bond and protect better. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140922/6886f70e/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
I think you're fighting a losing battle. Different alloys have an influence, but not enough to overcome the fact that copper has roughly twice the conductivity (both electrical and thermal) of aluminum. You'll need twice the cross-sectional area in aluminum as you would need with copper to achieve similar performance. Your 1.75 inch test shows a lack of proportionality, but that's likely due to short straps and how the current flows locally from the bolted joint. I'm thinking your best bet is to use copper conductors and be very sure all connections are thoroughly greased (Noalox, Vaseline, whatever) to ensure all moisture is excluded from the joint. And I would re-grease them once a year. Chris On Sun, Sep 21, 2014 at 2:54 AM, via EV ev@lists.evdl.org wrote: I thought folks would like to hear the results of some of my testing. 1/2 inch smashed copper pipe, 200 Amps for a 2S2P pack of 8 Ahr P (for Power) Headway cells: Things stayed cool. 1/2 inch by 0.02 inch braided strap with smashed copper pipe at connections: 5 F rise in 90 seconds at 200 A 1/2 inch by 0.01 inch Al: 200A, 80F to 200F in about 15 seconds! This was done in the oxidized state. 1/2 inch by 0.01 inch Al: 200A, 80F to 200F in about 15 seconds! This was done with sanding and immediate Noalox. 1.75 inch by 0.02 inch Al: 200A, 80F to 160F in about 30 seconds. The Al performed way worse than theory predicted, then I think I figured it out. Al roof flashing from Home Depot is apparently not a very conductive alloy of Al. I'd guess better Al would perform much closer to Cu. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140921/5d7baf7c/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
I might well be fighting a losing battle, but for the price of 4 holes in a strip of material it has been a great education. Tonight I tested the different alloys of Al idea. Last time, 0.02 x 1.75 in strip of roof flashing aluminum: ~120 F temperature rise in ~15 seconds, cross sectional area 0.036 in^2 Tonight: 0.1 in diameter aluminum welding filler rod ~30 F temperature rise in ~90 seconds, cross sectional area 0.016 in^2 I was rather impressed that 1/2 the area had ~1/4 the temperature rise! My guess is the welding rod is a more conductive Al alloy than the roof flashing is the big difference. Sent: Sunday, September 21, 2014 at 11:03 AM From: Chris Tromley ctrom...@gmail.com To: evdragra...@email.com, Electric Vehicle Discussion List ev@lists.evdl.org Subject: Re: [EVDL] Dissimilar metals on Headyways? I think you're fighting a losing battle. Different alloys have an influence, but not enough to overcome the fact that copper has roughly twice the conductivity (both electrical and thermal) of aluminum. You'll need twice the cross-sectional area in aluminum as you would need with copper to achieve similar performance. Your 1.75 inch test shows a lack of proportionality, but that's likely due to short straps and how the current flows locally from the bolted joint. I'm thinking your best bet is to use copper conductors and be very sure all connections are thoroughly greased (Noalox, Vaseline, whatever) to ensure all moisture is excluded from the joint. And I would re-grease them once a year. Chris On Sun, Sep 21, 2014 at 2:54 AM, via EV ev@lists.evdl.org wrote:I thought folks would like to hear the results of some of my testing. 1/2 inch smashed copper pipe, 200 Amps for a 2S2P pack of 8 Ahr P (for Power) Headway cells: Things stayed cool. 1/2 inch by 0.02 inch braided strap with smashed copper pipe at connections: 5 F rise in 90 seconds at 200 A 1/2 inch by 0.01 inch Al: 200A, 80F to 200F in about 15 seconds! This was done in the oxidized state. 1/2 inch by 0.01 inch Al: 200A, 80F to 200F in about 15 seconds! This was done with sanding and immediate Noalox. 1.75 inch by 0.02 inch Al: 200A, 80F to 160F in about 30 seconds. The Al performed way worse than theory predicted, then I think I figured it out. Al roof flashing from Home Depot is apparently not a very conductive alloy of Al. I'd guess better Al would perform much closer to Cu. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub[http://www.evdl.org/help/index.html#usub] http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA[http://groups.yahoo.com/group/NEDRA]) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
via EV wrote: I might well be fighting a losing battle, but for the price of 4 holes in a strip of material it has been a great education. Tonight I tested the different alloys of Al idea. Last time, 0.02 x 1.75 in strip of roof flashing aluminum: ~120 F temperature rise in ~15 seconds, cross sectional area 0.036 in^2 Tonight: 0.1 in diameter aluminum welding filler rod ~30 F temperature rise in ~90 seconds, cross sectional area 0.016 in^2 I was rather impressed that 1/2 the area had ~1/4 the temperature rise! My guess is the welding rod is a more conductive Al alloy than the roof flashing is the big difference. Great to see some actual test results! A quick comment: Pure metals are much more conductive than alloys. Most hardware store structural aluminum is going to be some alloy -- not what you want as an electrical conductor! Look up the conductivity of the various aluminum alloys and you'll see what I mean. Get some PURE aluminum to test. If you have to get it at Home Depot, then buy some aluminum *wire* and spread out the strands to make a flat strip. There are also aluminum solders. They actually work pretty well. You could place a bunch of strands of aluminum wire next to each other to make a flat bar, wrap a thin piece of aluminum flashing around them to hold them in position, and then solder them together at the ends. Drill a hole in the ends of the bar, and you have a high conductivity (yet somewhat flexible) inter-cell jumper. -- If you would not be forgotten When your body's dead and rotten Then write of great deeds worth the reading Or do these great deeds, worth repeating. -- Ben Franklin, from Poor Richard's Almanac -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140919/4cb2b0e2/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
argh, stupid mailer keeps defaulting to html. Anyway, here's the post again: This guy on endless-sphere cut one apart and says there is aluminum below the steel screw part: http://www.endless-sphere.com/forums/viewtopic.php?f=14t=8109hilit=BMI+inside So my basic question is if the cell is already Al to Steel internally, might it be better to go Al to Steel to Al (that last Al being my intercell connectors) than to do Al to Steel to Cu (which would be copper intercell connectors)? ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
via EV wrote: So my basic question is if the cell is already Al to Steel internally, might it be better to go Al to Steel to Al (that last Al being my intercell connectors) than to do Al to Steel to Cu (which would be copper intercell connectors)? What little I know about metallurgy tells me that attaching steel to aluminum is a bad idea. Maybe it can be done right by experts with special techniques. Others who are knowledgeable about such things may have more data with references. But it's something that would normally be avoided. Just because the Chinese did it does not make it good practice (they favor cheap, not good). Certainly, for connections outside the cell in the real world of water, oxygen, dirt, corrosion, etc. I would definitely avoid it. If you insist on doing this anyway, then you should plan to measure the actual resistance of each and every connection. -- If you would not be forgotten When your body's dead and rotten Then write of great deeds worth the reading Or do these great deeds, worth repeating. -- Ben Franklin, from Poor Richard's Almanac -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
Why do we think the cap is steel? Nickel is a better choice if you don't look at cost. Or a bonded bimetal. There are probably ways to do a good job of this. I have cooking pots that are aluminum bonded to stainless steel. Like wise copper to stainless. I have used silver bonded to brass (admittedly not a bad combination as we might assume aluminum to be). Anyway, if you get a good fusion bond then you can stop worrying about the dissimilar metals bit because no moisture can be involved. Earlier this year someone mentioned that the conductivity of stainless is far less than that of nickel, however the conductivity of wire is expressed as cross section and length. That means you can have a connection with a enough cross section and very short length and the resistance does not sum up to anything worth worrying about. One thing I have not sorted out yet - the choices of electrode materials in Li ion batteries. I have heard that it doesn't matter that one is copper and the other aluminum - could be two of copper, or presumable two of aluminum, or two of nickel. Given what can go awry with stacks of thin aluminum electrodes clamped together with a terminal - what makes that a common choice? On Fri, Sep 19, 2014 at 12:39 PM, Lee Hart via EV ev@lists.evdl.org wrote: via EV wrote: So my basic question is if the cell is already Al to Steel internally, might it be better to go Al to Steel to Al (that last Al being my intercell connectors) than to do Al to Steel to Cu (which would be copper intercell connectors)? What little I know about metallurgy tells me that attaching steel to aluminum is a bad idea. Maybe it can be done right by experts with special techniques. Others who are knowledgeable about such things may have more data with references. But it's something that would normally be avoided. Just because the Chinese did it does not make it good practice (they favor cheap, not good). Certainly, for connections outside the cell in the real world of water, oxygen, dirt, corrosion, etc. I would definitely avoid it. If you insist on doing this anyway, then you should plan to measure the actual resistance of each and every connection. -- If you would not be forgotten When your body's dead and rotten Then write of great deeds worth the reading Or do these great deeds, worth repeating. -- Ben Franklin, from Poor Richard's Almanac -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/ group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140919/87c00b90/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
Wow, I can't believe they actually used steel in those connections. I had heard about it but presumed people were confusing nickel-plating with steel. Nope, that is steel with rust an everything. Stay away! On Thu, Sep 18, 2014 at 9:21 PM, EVDL Administrator via EV ev@lists.evdl.org wrote: On 19 Sep 2014 at 5:30, via EV wrote: An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140919/b9981ecd/attachment.htm Please post in plain text, or use a mail system / client that knows how to send multipart MIME. Sorry for the inconvenience. The HTML message quarantined on the server includes a link to the Endless Sphere ebike forum, and disassembly of a headway cell. http://www.endless- sphere.com/forums/viewtopic.php?f=14t=8109hilit=BMI+inside One photo seems to show an aluminum contact disc WELDED to a steel baseplate into which the terminal screw is threaded. I didn't expect to see that. As I wrote before, I can't see how using aluminum intercell connectors would help. On the contrary, in fact. You'd be adding yet another junction between dissimilar metals. I'd probably use Headway's own (plated?) cell interconnects and be done with it. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- www.electric-lemon.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140919/b88ff1c1/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
A magnet sticks to the end, and there are people that have had the ends rust, so it looks like the cell ends are steel. Folks on endless-sphere think that is for strength for the screws. I have run 100 A for 90 seconds through the cells, and the ends were cool afterwards (using Cu intercell connectors). I'm measuring 6 milliOhms internal resistance, not bad for an 8 Ahr cell. Just for fun I'll try it with Al to see if it runs hotter. I just ran across this, this page shows a galvanic corrosion chart: http://www.corrosionist.com/galvanic_corrosion_chart.htm It looks like steel to Al is about the same as steel to Cu, but Cu to Al is about twice as bad. Is it as simple as the chart or are there more things to worry about? Just thinking out loud, is a pressure contact more likely to have problems? Maybe that us why welding on tabs is so common (thanks for the Cu and steel clad comments for inspiring that line of thought). Many thanks for all the the good inputs. -Original message- Sent: Friday, 19 September 2014 at 18:51:18 From: Michael Ross via EV ev@lists.evdl.org To: Lee Hart leeah...@earthlink.net,Electric Vehicle Discussion List ev@lists.evdl.org Subject: Re: [EVDL] Dissimilar metals on Headyways? Why do we think the cap is steel? Nickel is a better choice if you don't look at cost. Or a bonded bimetal. There are probably ways to do a good job of this. I have cooking pots that are aluminum bonded to stainless steel. Like wise copper to stainless. I have used silver bonded to brass (admittedly not a bad combination as we might assume aluminum to be). Anyway, if you get a good fusion bond then you can stop worrying about the dissimilar metals bit because no moisture can be involved. Earlier this year someone mentioned that the conductivity of stainless is far less than that of nickel, however the conductivity of wire is expressed as cross section and length. That means you can have a connection with a enough cross section and very short length and the resistance does not sum up to anything worth worrying about. One thing I have not sorted out yet - the choices of electrode materials in Li ion batteries. I have heard that it doesn't matter that one is copper and the other aluminum - could be two of copper, or presumable two of aluminum, or two of nickel. Given what can go awry with stacks of thin aluminum electrodes clamped together with a terminal - what makes that a common choice? On Fri, Sep 19, 2014 at 12:39 PM, Lee Hart via EV ev@lists.evdl.org wrote: via EV wrote: So my basic question is if the cell is already Al to Steel internally, might it be better to go Al to Steel to Al (that last Al being my intercell connectors) than to do Al to Steel to Cu (which would be copper intercell connectors)? What little I know about metallurgy tells me that attaching steel to aluminum is a bad idea. Maybe it can be done right by experts with special techniques. Others who are knowledgeable about such things may have more data with references. But it's something that would normally be avoided. Just because the Chinese did it does not make it good practice (they favor cheap, not good). Certainly, for connections outside the cell in the real world of water, oxygen, dirt, corrosion, etc. I would definitely avoid it. If you insist on doing this anyway, then you should plan to measure the actual resistance of each and every connection. -- If you would not be forgotten When your body's dead and rotten Then write of great deeds worth the reading Or do these great deeds, worth repeating. -- Ben Franklin, from Poor Richard's Almanac -- Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/ group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140919/87c00b90/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http
Re: [EVDL] Dissimilar metals on Headyways?
Since they have a stamped and formed end that is threaded, then steel makes sense to allow good clamping force with little thread engagement. Extruding a hole like that and then tapping it is a good practice, economical and effective. The extrusion work hardens the steel - even better. Reviewing the image again, the thing is probably nickel plated. It doesn't look bad on the outside. But electroplating down in a depression is dicey,and it is probably thin there, hence the corrosion underneath there. I wouldn't call these spot welds as spot welding is usually done by trapping the two pieces between two electrodes across the thickness of the material, these are probably little TIG zaps around the perimeter. I have never seen anything quite like that before. I don't see anything alarming about that from an electrical conduction POV, probably not a very strong joint physically, but it might not be a problem. I don't see that the rust is a problem either, just don't submerge or spray them with salt water. At any rate I don't find this as alarming as some folks. It may be better than machined, drilled and tapped aluminum pods for bolting. The fellow who took the pictures mentioned glue between the aluminum and steel - I am thinking sealant not adhesive. If the welds fail the glue would be pointless - sealant however... I really like reverse engineering stuff. I have a small Headway pack. Now I can't wait for it to give out someday so I can check it out. A note on galvanic corrosion - it is not a concern with fused joints or if there is no mositure. On Fri, Sep 19, 2014 at 7:05 PM, via EV ev@lists.evdl.org wrote: A magnet sticks to the end, and there are people that have had the ends rust, so it looks like the cell ends are steel. Folks on endless-sphere think that is for strength for the screws. I have run 100 A for 90 seconds through the cells, and the ends were cool afterwards (using Cu intercell connectors). I'm measuring 6 milliOhms internal resistance, not bad for an 8 Ahr cell. Just for fun I'll try it with Al to see if it runs hotter. I just ran across this, this page shows a galvanic corrosion chart: http://www.corrosionist.com/galvanic_corrosion_chart.htm It looks like steel to Al is about the same as steel to Cu, but Cu to Al is about twice as bad. Is it as simple as the chart or are there more things to worry about? Just thinking out loud, is a pressure contact more likely to have problems? Maybe that us why welding on tabs is so common (thanks for the Cu and steel clad comments for inspiring that line of thought). Many thanks for all the the good inputs. -Original message- Sent: Friday, 19 September 2014 at 18:51:18 From: Michael Ross via EV ev@lists.evdl.org To: Lee Hart leeah...@earthlink.net,Electric Vehicle Discussion List ev@lists.evdl.org Subject: Re: [EVDL] Dissimilar metals on Headyways? Why do we think the cap is steel? Nickel is a better choice if you don't look at cost. Or a bonded bimetal. There are probably ways to do a good job of this. I have cooking pots that are aluminum bonded to stainless steel. Like wise copper to stainless. I have used silver bonded to brass (admittedly not a bad combination as we might assume aluminum to be). Anyway, if you get a good fusion bond then you can stop worrying about the dissimilar metals bit because no moisture can be involved. Earlier this year someone mentioned that the conductivity of stainless is far less than that of nickel, however the conductivity of wire is expressed as cross section and length. That means you can have a connection with a enough cross section and very short length and the resistance does not sum up to anything worth worrying about. One thing I have not sorted out yet - the choices of electrode materials in Li ion batteries. I have heard that it doesn't matter that one is copper and the other aluminum - could be two of copper, or presumable two of aluminum, or two of nickel. Given what can go awry with stacks of thin aluminum electrodes clamped together with a terminal - what makes that a common choice? On Fri, Sep 19, 2014 at 12:39 PM, Lee Hart via EV ev@lists.evdl.org wrote: via EV wrote: So my basic question is if the cell is already Al to Steel internally, might it be better to go Al to Steel to Al (that last Al being my intercell connectors) than to do Al to Steel to Cu (which would be copper intercell connectors)? What little I know about metallurgy tells me that attaching steel to aluminum is a bad idea. Maybe it can be done right by experts with special techniques. Others who are knowledgeable about such things may have more data with references. But it's something that would normally be avoided. Just because the Chinese did it does not make it good practice (they favor cheap, not good). Certainly, for connections outside the cell in the real world of water, oxygen, dirt, corrosion, etc. I
Re: [EVDL] Dissimilar metals on Headyways?
An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140919/b9981ecd/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
On 19 Sep 2014 at 5:30, via EV wrote: An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140919/b9981ecd/attachment.htm Please post in plain text, or use a mail system / client that knows how to send multipart MIME. Sorry for the inconvenience. The HTML message quarantined on the server includes a link to the Endless Sphere ebike forum, and disassembly of a headway cell. http://www.endless- sphere.com/forums/viewtopic.php?f=14t=8109hilit=BMI+inside One photo seems to show an aluminum contact disc WELDED to a steel baseplate into which the terminal screw is threaded. I didn't expect to see that. As I wrote before, I can't see how using aluminum intercell connectors would help. On the contrary, in fact. You'd be adding yet another junction between dissimilar metals. I'd probably use Headway's own (plated?) cell interconnects and be done with it. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
This guy on endless_sphere cut one apart and says there is aluminum below the steel screw part: Nothing unusual about this - the electrodes are often Cu, and Al.all the leaves of Al electrodes have to be gather together and clamped somehow.RGw out side of the cell is a plated stamped metal. I think all of us were assuming you were talking about the outermost connection. Again I suggest you link us to an image showing that you are talking about. Once again you have posted in a format that is not acceptable to the list server and the message was scrubbed. This will limit the number of people who are willing to read and answer what you are posting. On Thu, Sep 18, 2014 at 11:30 PM, via EV ev@lists.evdl.org wrote: An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140919/b9981ecd/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140919/e74cf880/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
Are you sure the ends are aluminium? Without the screw terminals they are connected by nickel strips spot welded to the ends, not sure you can spot weld nickel to aluminium. I think they are plated steel. -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of via EV Sent: Wednesday, 17 September 2014 3:34 p.m. To: ev@lists.evdl.org Subject: [EVDL] Dissimilar metals on Headyways? I'm building up some headway packs. My understanding is they have aluminum end caps in the bare state, but when you get them with screw terminals the screw terminals are steel and sit on the aluminum. Might this make it better to wire them together with Aluminum plates rather than Copper plates? Does solder dipping the plate help? Thanks for the advice. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
How about a photo or spec sheet to look at? You say Headway, do they only make on sized and form of cell? On Tue, Sep 16, 2014 at 11:34 PM, via EV ev@lists.evdl.org wrote: I'm building up some headway packs. My understanding is they have aluminum end caps in the bare state, but when you get them with screw terminals the screw terminals are steel and sit on the aluminum. Might this make it better to wire them together with Aluminum plates rather than Copper plates? Does solder dipping the plate help? Thanks for the advice. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140917/385442ef/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] Dissimilar metals on Headyways?
I have both types, just checked them, no sign of aluminium anywhere -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Michael Ross via EV Sent: Thursday, 18 September 2014 11:43 a.m. To: evdragra...@email.com; Electric Vehicle Discussion List Subject: Re: [EVDL] Dissimilar metals on Headyways? How about a photo or spec sheet to look at? You say Headway, do they only make on sized and form of cell? On Tue, Sep 16, 2014 at 11:34 PM, via EV ev@lists.evdl.org wrote: I'm building up some headway packs. My understanding is they have aluminum end caps in the bare state, but when you get them with screw terminals the screw terminals are steel and sit on the aluminum. Might this make it better to wire them together with Aluminum plates rather than Copper plates? Does solder dipping the plate help? Thanks for the advice. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, The summer day. To invent, you need a good imagination and a pile of junk. Thomas A. Edison http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140917/385442ef /attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
